The Caesar Cipher

Secret codes began thousands of years ago when people needed to write messages without the danger of the enemy intercepting them. One of the first and simplest codes to ever be used is called the Caesar Cipher. Caesar Ciphers are some of the easiest to create, yet some of the easiest to break.

The Caesar Cipher, named after Julius Caesar (who used it), works by shifting the letters in the alphabet a few letters forward or backward, making the message appear unreadable. If we were to shift two letters forward, the letter A would become the letter C. The message “ATTACK AT DAWN” would turn into “CVVCEM CV FCYP.” This way, if an enemy intercepted your message, it would appear unreadable. If your ally received your letter, they would be able to look at your message and shift two backward, revealing the true message.

These ciphers are easier to break than many more complicated ciphers, like the Vigenère cipher or Pigpen cipher. The best way to break the Caesar Cipher is with a mix between frequency analysis and brute force attacks.

The most common letter in the alphabet is the letter E, so if you look at a message encoded in the Caesar Cipher, the most common letter in the message will likely be E. This simple method is called frequency analysis, and it makes the Caesar Cipher much easier to break.

Caesar Ciphers are recommended for quick notes you pass to your friends that you don’t want teachers reading or other things you want to keep kind of secret from regular people, but if someone tried hard enough to decode it, they could.

Now that you’ve learned some things about the Caesar Cipher, here’s a slightly altered version. Every letter represents another letter, but it comes with a twist. Comment if you manage to solve!